Data from Net Applications -- which lumps mobile and desktop operating systems into one statistic -- show that Windows market share dropped from 93.74% in February 2009 to 90.29% in December 2010. Windows was still above 92% market share as recently as February 2010 but suffered steady losses during the rest of the year.
"The operating system usage market share trend line points to Windows' overall usage falling below 90% sometime during 2011," says Vince Vizzaccaro, executive vice president of marketing and strategic alliances for Net Applications. "The timing depends on several market forces. It could be as early as next month, or possibly not at all."
Microsoft's continued dominance of the desktop operating system market will likely not be enough to keep Windows' total share above 90%, because the proliferation of smartphones and tablets is changing the definition of what a personal computer is. Microsoft's mobile efforts revolving around Windows Phone 7 and Windows 7 in tablets will be crucial for Redmond.
IT analyst Jack Gold, writing in TheStreet.com, predicts "By 2013, greater than 67% of browsers accessing the Internet will be on non-PC devices. Internet Explorer will ultimately become a minor player in the browser market, with WebKit-based rendering engines powering the majority of mobile devices, and Mozilla-based browsers being deployed on Linux-based (and Meego-based) larger form factor products. As a result, websites will no longer be optimized for PC-based Internet Explorer, but will standardize on WebKit and HTML5 for broad-based browser compatibility."
For now, though, most personal computing is still performed through Windows. StatCounter, another market share tracker similar to Net Applications, reports desktop and mobile operating system share separately, instead of combining them into one statistic. The combined desktop share of Windows XP, Vista and 7 is still at 91.94%, compared to 6.25% for Mac OS X and 0.75% for Linux, StatCounter's figures show.
Microsoft can expect increasing revenue for Windows, simply because PC shipments are expected to rise in both 2011 and 2012, according to IDC. So it may not be that Windows is getting smaller -- it's more that the rest of the market, driven by mobile devices, is getting bigger and Microsoft isn't capitalizing on the growth. More and more users are accessing the Internet on devices that don't run Windows.
"I have no doubt that the number of Windows users has grown significantly over 2010, and am equally confident in growth in the number of users of Mac OS in 2010," Vizzaccaro says. "What we're seeing is faster growth in mobile and tablet usage. I don't think Windows Phone 7 has been on the market long enough yet to help Microsoft on the mobile front, but I do believe Microsoft recognizes how important the mobile arena is, and is focused on being successful there."
While Net Applications' data shows Windows' market share dropping from 93.74% in February 2009 to 90.29% in December 2010, Mac moved from 4.55% to 5.02% in the same time frame. Net Applications collects its data from about 40,000 websites, counting unique visitors, specifically "one unique visit to each network site per day."
Linux held steady, sticking at about 0.96%. But Apple's iOS rose from 0.23% in February 2009 to 1.69% in December 2010. Android only accounts for 0.40% of operating systems but is on the upswing. Java ME quadrupled share from 0.23% to 0.91% in the past two years.
Microsoft has also long dominated the browser market because most Windows users surf the Web with Internet Explorer, the OS's built-in browser. But the rise of viable alternatives such as Mozilla's Firefox and Google Chrome has eaten into Microsoft's browser share as well.
Internet Explorer share dropped from 69.72% in January 2009 to 57.08% in December 2010, according to Net Applications data, with Firefox holding steady in the 22% range and Chrome rocketing up from 1.52% to 9.98%.
StatCounter's figures show even more depressing news for Microsoft on the browser front. StatCounter has Internet Explorer usage dropping to 46.94% in December, with more than half of all Web browsing now taking place on Firefox, Chrome and the Mac's Safari.
While Net Applications tracks only unique visitors, StatCounter's numbers compile all the hits across a network of 3 million websites. One possible explanation for the difference between Net Applications and StatCounter browsing data is that the most active Web users choose Firefox and Chrome instead of Internet Explorer. In that scenario, most computer users would surf the Web with Internet Explorer, but the majority of total browsing would occur on non-Microsoft browsers. But further research is probably necessary to make that determination.
In an e-mail response to Network World, StatCounter says "It is certainly possible that Firefox and Chrome users could consume more pageviews per day than IE users ... however we haven't established any evidence to that effect ourselves."
Read more about software in Network World's Software section.